Merge branch 'sp/help'

* sp/help:
  shell should call the new setup_path() to setup $PATH
  include $PATH in generating list of commands for "help -a"
  use only the $PATH for exec'ing git commands
  list_commands(): simplify code by using chdir()
  "current_exec_path" is a misleading name, use "argv_exec_path"
  remove unused/unneeded "pattern" argument of list_commands
  "git" returns 1; "git help" and "git help -a" return 0

6 files changed, 203 insertions, 178 deletions

diff --git a/builtin.h b/builtin.h
index 65cc0fb34a..9a6213af12 100644
--- a/builtin.h
+++ b/builtin.h
@@ -6,6 +6,7 @@
 extern const char git_version_string[];
 extern const char git_usage_string[];
 
+extern void list_common_cmds_help(void);
 extern void help_unknown_cmd(const char *cmd);
 extern int write_tree(unsigned char *sha1, int missing_ok, const char *prefix);
 extern void prune_packed_objects(int);
diff --git a/exec_cmd.c b/exec_cmd.c
index 9b74ed2f42..2d0a758512 100644
--- a/exec_cmd.c
+++ b/exec_cmd.c
@@ -5,11 +5,11 @@
 
 extern char **environ;
 static const char *builtin_exec_path = GIT_EXEC_PATH;
-static const char *current_exec_path;
+static const char *argv_exec_path;
 
-void git_set_exec_path(const char *exec_path)
+void git_set_argv_exec_path(const char *exec_path)
 {
-	current_exec_path = exec_path;
+	argv_exec_path = exec_path;
 }
 
 
@@ -18,8 +18,8 @@ const char *git_exec_path(void)
 {
 	const char *env;
 
-	if (current_exec_path)
-		return current_exec_path;
+	if (argv_exec_path)
+		return argv_exec_path;
 
 	env = getenv(EXEC_PATH_ENVIRONMENT);
 	if (env && *env) {
@@ -29,85 +29,69 @@ const char *git_exec_path(void)
 	return builtin_exec_path;
 }
 
+static void add_path(struct strbuf *out, const char *path)
+{
+	if (path && *path) {
+		if (is_absolute_path(path))
+			strbuf_addstr(out, path);
+		else
+			strbuf_addstr(out, make_absolute_path(path));
+
+		strbuf_addch(out, ':');
+	}
+}
+
+void setup_path(const char *cmd_path)
+{
+	const char *old_path = getenv("PATH");
+	struct strbuf new_path;
+
+	strbuf_init(&new_path, 0);
+
+	add_path(&new_path, argv_exec_path);
+	add_path(&new_path, getenv(EXEC_PATH_ENVIRONMENT));
+	add_path(&new_path, builtin_exec_path);
+	add_path(&new_path, cmd_path);
+
+	if (old_path)
+		strbuf_addstr(&new_path, old_path);
+	else
+		strbuf_addstr(&new_path, "/usr/local/bin:/usr/bin:/bin");
+
+	setenv("PATH", new_path.buf, 1);
+
+	strbuf_release(&new_path);
+}
 
 int execv_git_cmd(const char **argv)
 {
-	char git_command[PATH_MAX + 1];
-	int i;
-	const char *paths[] = { current_exec_path,
-				getenv(EXEC_PATH_ENVIRONMENT),
-				builtin_exec_path };
-
-	for (i = 0; i < ARRAY_SIZE(paths); ++i) {
-		size_t len;
-		int rc;
-		const char *exec_dir = paths[i];
-		const char *tmp;
-
-		if (!exec_dir || !*exec_dir) continue;
-
-		if (*exec_dir != '/') {
-			if (!getcwd(git_command, sizeof(git_command))) {
-				fprintf(stderr, "git: cannot determine "
-					"current directory: %s\n",
-					strerror(errno));
-				break;
-			}
-			len = strlen(git_command);
-
-			/* Trivial cleanup */
-			while (!prefixcmp(exec_dir, "./")) {
-				exec_dir += 2;
-				while (*exec_dir == '/')
-					exec_dir++;
-			}
-
-			rc = snprintf(git_command + len,
-				      sizeof(git_command) - len, "/%s",
-				      exec_dir);
-			if (rc < 0 || rc >= sizeof(git_command) - len) {
-				fprintf(stderr, "git: command name given "
-					"is too long.\n");
-				break;
-			}
-		} else {
-			if (strlen(exec_dir) + 1 > sizeof(git_command)) {
-				fprintf(stderr, "git: command name given "
-					"is too long.\n");
-				break;
-			}
-			strcpy(git_command, exec_dir);
-		}
-
-		len = strlen(git_command);
-		rc = snprintf(git_command + len, sizeof(git_command) - len,
-			      "/git-%s", argv[0]);
-		if (rc < 0 || rc >= sizeof(git_command) - len) {
-			fprintf(stderr,
-				"git: command name given is too long.\n");
-			break;
-		}
+	struct strbuf cmd;
+	const char *tmp;
 
-		/* argv[0] must be the git command, but the argv array
-		 * belongs to the caller, and my be reused in
-		 * subsequent loop iterations. Save argv[0] and
-		 * restore it on error.
-		 */
+	strbuf_init(&cmd, 0);
+	strbuf_addf(&cmd, "git-%s", argv[0]);
 
-		tmp = argv[0];
-		argv[0] = git_command;
+	/*
+	 * argv[0] must be the git command, but the argv array
+	 * belongs to the caller, and may be reused in
+	 * subsequent loop iterations. Save argv[0] and
+	 * restore it on error.
+	 */
+	tmp = argv[0];
+	argv[0] = cmd.buf;
 
-		trace_argv_printf(argv, -1, "trace: exec:");
+	trace_argv_printf(argv, -1, "trace: exec:");
 
-		/* execve() can only ever return if it fails */
-		execve(git_command, (char **)argv, environ);
+	/* execvp() can only ever return if it fails */
+	execvp(cmd.buf, (char **)argv);
 
-		trace_printf("trace: exec failed: %s\n", strerror(errno));
+	trace_printf("trace: exec failed: %s\n", strerror(errno));
 
-		argv[0] = tmp;
-	}
-	return -1;
+	argv[0] = tmp;
 
+	strbuf_release(&cmd);
+
+	return -1;
 }
 
 
diff --git a/exec_cmd.h b/exec_cmd.h
index 849a8395a0..a892355c82 100644
--- a/exec_cmd.h
+++ b/exec_cmd.h
@@ -1,8 +1,9 @@
 #ifndef GIT_EXEC_CMD_H
 #define GIT_EXEC_CMD_H
 
-extern void git_set_exec_path(const char *exec_path);
+extern void git_set_argv_exec_path(const char *exec_path);
 extern const char* git_exec_path(void);
+extern void setup_path(const char *);
 extern int execv_git_cmd(const char **argv); /* NULL terminated */
 extern int execl_git_cmd(const char *cmd, ...);
 
diff --git a/git.c b/git.c
index 23a430c369..4e10581101 100644
--- a/git.c
+++ b/git.c
@@ -6,28 +6,6 @@
 const char git_usage_string[] =
 	"git [--version] [--exec-path[=GIT_EXEC_PATH]] [-p|--paginate|--no-pager] [--bare] [--git-dir=GIT_DIR] [--work-tree=GIT_WORK_TREE] [--help] COMMAND [ARGS]";
 
-static void prepend_to_path(const char *dir, int len)
-{
-	const char *old_path = getenv("PATH");
-	char *path;
-	int path_len = len;
-
-	if (!old_path)
-		old_path = "/usr/local/bin:/usr/bin:/bin";
-
-	path_len = len + strlen(old_path) + 1;
-
-	path = xmalloc(path_len + 1);
-
-	memcpy(path, dir, len);
-	path[len] = ':';
-	memcpy(path + len + 1, old_path, path_len - len);
-
-	setenv("PATH", path, 1);
-
-	free(path);
-}
-
 static int handle_options(const char*** argv, int* argc, int* envchanged)
 {
 	int handled = 0;
@@ -51,7 +29,7 @@ static int handle_options(const char*** argv, int* argc, int* envchanged)
 		if (!prefixcmp(cmd, "--exec-path")) {
 			cmd += 11;
 			if (*cmd == '=')
-				git_set_exec_path(cmd + 1);
+				git_set_argv_exec_path(cmd + 1);
 			else {
 				puts(git_exec_path());
 				exit(0);
@@ -408,7 +386,7 @@ int main(int argc, const char **argv)
 {
 	const char *cmd = argv[0] ? argv[0] : "git-help";
 	char *slash = strrchr(cmd, '/');
-	const char *exec_path = NULL;
+	const char *cmd_path = NULL;
 	int done_alias = 0;
 
 	/*
@@ -418,10 +396,7 @@ int main(int argc, const char **argv)
 	 */
 	if (slash) {
 		*slash++ = 0;
-		if (*cmd == '/')
-			exec_path = cmd;
-		else
-			exec_path = xstrdup(make_absolute_path(cmd));
+		cmd_path = cmd;
 		cmd = slash;
 	}
 
@@ -450,23 +425,20 @@ int main(int argc, const char **argv)
 		if (!prefixcmp(argv[0], "--"))
 			argv[0] += 2;
 	} else {
-		/* Default command: "help" */
-		argv[0] = "help";
-		argc = 1;
+		/* The user didn't specify a command; give them help */
+		printf("usage: %s\n\n", git_usage_string);
+		list_common_cmds_help();
+		exit(1);
 	}
 	cmd = argv[0];
 
 	/*
-	 * We execute external git command via execv_git_cmd(),
-	 * which looks at "--exec-path" option, GIT_EXEC_PATH
-	 * environment, and $(gitexecdir) in Makefile while built,
-	 * in this order.  For scripted commands, we prepend
-	 * the value of the exec_path variable to the PATH.
+	 * We use PATH to find git commands, but we prepend some higher
+	 * precidence paths: the "--exec-path" option, the GIT_EXEC_PATH
+	 * environment, and the $(gitexecdir) from the Makefile at build
+	 * time.
 	 */
-	if (exec_path)
-		prepend_to_path(exec_path, strlen(exec_path));
-	exec_path = git_exec_path();
-	prepend_to_path(exec_path, strlen(exec_path));
+	setup_path(cmd_path);
 
 	while (1) {
 		/* See if it's an internal command */
diff --git a/help.c b/help.c
index e5662d9014..855aeef92f 100644
--- a/help.c
+++ b/help.c
@@ -37,24 +37,25 @@ static inline void mput_char(char c, unsigned int num)
 		putchar(c);
 }
 
-static struct cmdname {
-	size_t len;
-	char name[1];
-} **cmdname;
-static int cmdname_alloc, cmdname_cnt;
-
-static void add_cmdname(const char *name, int len)
+static struct cmdnames {
+	int alloc;
+	int cnt;
+	struct cmdname {
+		size_t len;
+		char name[1];
+	} **names;
+} main_cmds, other_cmds;
+
+static void add_cmdname(struct cmdnames *cmds, const char *name, int len)
 {
-	struct cmdname *ent;
-	if (cmdname_alloc <= cmdname_cnt) {
-		cmdname_alloc = cmdname_alloc + 200;
-		cmdname = xrealloc(cmdname, cmdname_alloc * sizeof(*cmdname));
-	}
-	ent = xmalloc(sizeof(*ent) + len);
+	struct cmdname *ent = xmalloc(sizeof(*ent) + len);
+
 	ent->len = len;
 	memcpy(ent->name, name, len);
 	ent->name[len] = 0;
-	cmdname[cmdname_cnt++] = ent;
+
+	ALLOC_GROW(cmds->names, cmds->cnt + 1, cmds->alloc);
+	cmds->names[cmds->cnt++] = ent;
 }
 
 static int cmdname_compare(const void *a_, const void *b_)
@@ -64,7 +65,42 @@ static int cmdname_compare(const void *a_, const void *b_)
 	return strcmp(a->name, b->name);
 }
 
-static void pretty_print_string_list(struct cmdname **cmdname, int longest)
+static void uniq(struct cmdnames *cmds)
+{
+	int i, j;
+
+	if (!cmds->cnt)
+		return;
+
+	for (i = j = 1; i < cmds->cnt; i++)
+		if (strcmp(cmds->names[i]->name, cmds->names[i-1]->name))
+			cmds->names[j++] = cmds->names[i];
+
+	cmds->cnt = j;
+}
+
+static void exclude_cmds(struct cmdnames *cmds, struct cmdnames *excludes) {
+	int ci, cj, ei;
+	int cmp;
+
+	ci = cj = ei = 0;
+	while (ci < cmds->cnt && ei < excludes->cnt) {
+		cmp = strcmp(cmds->names[ci]->name, excludes->names[ei]->name);
+		if (cmp < 0)
+			cmds->names[cj++] = cmds->names[ci++];
+		else if (cmp == 0)
+			ci++, ei++;
+		else if (cmp > 0)
+			ei++;
+	}
+
+	while (ci < cmds->cnt)
+		cmds->names[cj++] = cmds->names[ci++];
+
+	cmds->cnt = cj;
+}
+
+static void pretty_print_string_list(struct cmdnames *cmds, int longest)
 {
 	int cols = 1, rows;
 	int space = longest + 1; /* min 1 SP between words */
@@ -73,9 +109,7 @@ static void pretty_print_string_list(struct cmdname **cmdname, int longest)
 
 	if (space < max_cols)
 		cols = max_cols / space;
-	rows = (cmdname_cnt + cols - 1) / cols;
-
-	qsort(cmdname, cmdname_cnt, sizeof(*cmdname), cmdname_compare);
+	rows = (cmds->cnt + cols - 1) / cols;
 
 	for (i = 0; i < rows; i++) {
 		printf("  ");
@@ -83,71 +117,112 @@ static void pretty_print_string_list(struct cmdname **cmdname, int longest)
 		for (j = 0; j < cols; j++) {
 			int n = j * rows + i;
 			int size = space;
-			if (n >= cmdname_cnt)
+			if (n >= cmds->cnt)
 				break;
-			if (j == cols-1 || n + rows >= cmdname_cnt)
+			if (j == cols-1 || n + rows >= cmds->cnt)
 				size = 1;
-			printf("%-*s", size, cmdname[n]->name);
+			printf("%-*s", size, cmds->names[n]->name);
 		}
 		putchar('\n');
 	}
 }
 
-static void list_commands(const char *exec_path, const char *pattern)
+static unsigned int list_commands_in_dir(struct cmdnames *cmds,
+					 const char *path)
 {
 	unsigned int longest = 0;
-	char path[PATH_MAX];
-	int dirlen;
-	DIR *dir = opendir(exec_path);
+	const char *prefix = "git-";
+	int prefix_len = strlen(prefix);
+	DIR *dir = opendir(path);
 	struct dirent *de;
 
-	if (!dir) {
-		fprintf(stderr, "git: '%s': %s\n", exec_path, strerror(errno));
-		exit(1);
-	}
-
-	dirlen = strlen(exec_path);
-	if (PATH_MAX - 20 < dirlen) {
-		fprintf(stderr, "git: insanely long exec-path '%s'\n",
-			exec_path);
-		exit(1);
-	}
-
-	memcpy(path, exec_path, dirlen);
-	path[dirlen++] = '/';
+	if (!dir || chdir(path))
+		return 0;
 
 	while ((de = readdir(dir)) != NULL) {
 		struct stat st;
 		int entlen;
 
-		if (prefixcmp(de->d_name, "git-"))
+		if (prefixcmp(de->d_name, prefix))
 			continue;
-		strcpy(path+dirlen, de->d_name);
-		if (stat(path, &st) || /* stat, not lstat */
+
+		if (stat(de->d_name, &st) || /* stat, not lstat */
 		    !S_ISREG(st.st_mode) ||
 		    !(st.st_mode & S_IXUSR))
 			continue;
 
-		entlen = strlen(de->d_name);
+		entlen = strlen(de->d_name) - prefix_len;
 		if (has_extension(de->d_name, ".exe"))
 			entlen -= 4;
 
 		if (longest < entlen)
 			longest = entlen;
 
-		add_cmdname(de->d_name + 4, entlen-4);
+		add_cmdname(cmds, de->d_name + prefix_len, entlen);
 	}
 	closedir(dir);
 
-	printf("git commands available in '%s'\n", exec_path);
-	printf("----------------------------");
-	mput_char('-', strlen(exec_path));
-	putchar('\n');
-	pretty_print_string_list(cmdname, longest - 4);
-	putchar('\n');
+	return longest;
 }
 
-static void list_common_cmds_help(void)
+static void list_commands(void)
+{
+	unsigned int longest = 0;
+	unsigned int len;
+	const char *env_path = getenv("PATH");
+	char *paths, *path, *colon;
+	const char *exec_path = git_exec_path();
+
+	if (exec_path)
+		longest = list_commands_in_dir(&main_cmds, exec_path);
+
+	if (!env_path) {
+		fprintf(stderr, "PATH not set\n");
+		exit(1);
+	}
+
+	path = paths = xstrdup(env_path);
+	while (1) {
+		if ((colon = strchr(path, ':')))
+			*colon = 0;
+
+		len = list_commands_in_dir(&other_cmds, path);
+		if (len > longest)
+			longest = len;
+
+		if (!colon)
+			break;
+		path = colon + 1;
+	}
+	free(paths);
+
+	qsort(main_cmds.names, main_cmds.cnt,
+	      sizeof(*main_cmds.names), cmdname_compare);
+	uniq(&main_cmds);
+
+	qsort(other_cmds.names, other_cmds.cnt,
+	      sizeof(*other_cmds.names), cmdname_compare);
+	uniq(&other_cmds);
+	exclude_cmds(&other_cmds, &main_cmds);
+
+	if (main_cmds.cnt) {
+		printf("available git commands in '%s'\n", exec_path);
+		printf("----------------------------");
+		mput_char('-', strlen(exec_path));
+		putchar('\n');
+		pretty_print_string_list(&main_cmds, longest);
+		putchar('\n');
+	}
+
+	if (other_cmds.cnt) {
+		printf("git commands available from elsewhere on your $PATH\n");
+		printf("---------------------------------------------------\n");
+		pretty_print_string_list(&other_cmds, longest);
+		putchar('\n');
+	}
+}
+
+void list_common_cmds_help(void)
 {
 	int i, longest = 0;
 
@@ -198,19 +273,17 @@ int cmd_version(int argc, const char **argv, const char *prefix)
 int cmd_help(int argc, const char **argv, const char *prefix)
 {
 	const char *help_cmd = argc > 1 ? argv[1] : NULL;
-	const char *exec_path = git_exec_path();
 
 	if (!help_cmd) {
 		printf("usage: %s\n\n", git_usage_string);
 		list_common_cmds_help();
-		exit(1);
+		exit(0);
 	}
 
 	else if (!strcmp(help_cmd, "--all") || !strcmp(help_cmd, "-a")) {
 		printf("usage: %s\n\n", git_usage_string);
-		if(exec_path)
-			list_commands(exec_path, "git-*");
-		exit(1);
+		list_commands();
+		exit(0);
 	}
 
 	else
diff --git a/shell.c b/shell.c
index cfe372b213..9826109d5b 100644
--- a/shell.c
+++ b/shell.c
@@ -24,17 +24,11 @@ static int do_cvs_cmd(const char *me, char *arg)
 	const char *cvsserver_argv[3] = {
 		"cvsserver", "server", NULL
 	};
-	const char *oldpath = getenv("PATH");
-	struct strbuf newpath = STRBUF_INIT;
 
 	if (!arg || strcmp(arg, "server"))
 		die("git-cvsserver only handles server: %s", arg);
 
-	strbuf_addstr(&newpath, git_exec_path());
-	strbuf_addch(&newpath, ':');
-	strbuf_addstr(&newpath, oldpath);
-
-	setenv("PATH", strbuf_detach(&newpath, NULL), 1);
+	setup_path(NULL);
 
 	return execv_git_cmd(cvsserver_argv);
 }